import argparse
import asyncio
import logging
import logging.handlers
import os
import platform
import sys
import socket
import json
import traceback

from grpc.experimental import aio as aiogrpc
from distutils.version import LooseVersion

import ray
import ray.dashboard.consts as dashboard_consts
import ray.dashboard.utils as dashboard_utils
import ray.ray_constants as ray_constants
import ray._private.services
import ray._private.utils
from ray.core.generated import agent_manager_pb2
from ray.core.generated import agent_manager_pb2_grpc
from ray._private.ray_logging import setup_component_logger
from ray._raylet import connect_to_gcs

# All third-party dependencies that are not included in the minimal Ray
# installation must be included in this file. This allows us to determine if
# the agent has the necessary dependencies to be started.
from ray.dashboard.optional_deps import aiohttp, aiohttp_cors, hdrs

# Import psutil after ray so the packaged version is used.
import psutil

try:
    create_task = asyncio.create_task
except AttributeError:
    create_task = asyncio.ensure_future

logger = logging.getLogger(__name__)
routes = dashboard_utils.ClassMethodRouteTable

aiogrpc.init_grpc_aio()


class DashboardAgent(object):
    def __init__(self,
                 node_ip_address,
                 redis_address,
                 dashboard_agent_port,
                 redis_password=None,
                 temp_dir=None,
                 session_dir=None,
                 runtime_env_dir=None,
                 log_dir=None,
                 metrics_export_port=None,
                 node_manager_port=None,
                 listen_port=0,
                 object_store_name=None,
                 raylet_name=None,
                 logging_params=None):
        """Initialize the DashboardAgent object."""
        # Public attributes are accessible for all agent modules.
        self.ip = node_ip_address
        self.redis_address = dashboard_utils.address_tuple(redis_address)
        self.redis_password = redis_password
        self.temp_dir = temp_dir
        self.session_dir = session_dir
        self.runtime_env_dir = runtime_env_dir
        self.log_dir = log_dir
        self.dashboard_agent_port = dashboard_agent_port
        self.metrics_export_port = metrics_export_port
        self.node_manager_port = node_manager_port
        self.listen_port = listen_port
        self.object_store_name = object_store_name
        self.raylet_name = raylet_name
        self.logging_params = logging_params
        self.node_id = os.environ["RAY_NODE_ID"]
        # TODO(edoakes): RAY_RAYLET_PID isn't properly set on Windows. This is
        # only used for fate-sharing with the raylet and we need a different
        # fate-sharing mechanism for Windows anyways.
        if sys.platform not in ["win32", "cygwin"]:
            self.ppid = int(os.environ["RAY_RAYLET_PID"])
            assert self.ppid > 0
            logger.info("Parent pid is %s", self.ppid)
        self.server = aiogrpc.server(options=(("grpc.so_reuseport", 0), ))
        self.grpc_port = ray._private.tls_utils.add_port_to_grpc_server(
            self.server, f"[::]:{self.dashboard_agent_port}")
        logger.info("Dashboard agent grpc address: %s:%s", self.ip,
                    self.grpc_port)
        self.aioredis_client = None
        options = (("grpc.enable_http_proxy", 0), )
        self.aiogrpc_raylet_channel = ray._private.utils.init_grpc_channel(
            f"{self.ip}:{self.node_manager_port}", options, asynchronous=True)
        self.http_session = None
        ip, port = redis_address.split(":")
        self.gcs_client = connect_to_gcs(ip, int(port), redis_password)

    def _load_modules(self):
        """Load dashboard agent modules."""
        modules = []
        agent_cls_list = dashboard_utils.get_all_modules(
            dashboard_utils.DashboardAgentModule)
        for cls in agent_cls_list:
            logger.info("Loading %s: %s",
                        dashboard_utils.DashboardAgentModule.__name__, cls)
            c = cls(self)
            dashboard_utils.ClassMethodRouteTable.bind(c)
            modules.append(c)
        logger.info("Loaded %d modules.", len(modules))
        return modules

    async def run(self):
        async def _check_parent():
            """Check if raylet is dead and fate-share if it is."""
            try:
                curr_proc = psutil.Process()
                while True:
                    parent = curr_proc.parent()
                    if (parent is None or parent.pid == 1
                            or self.ppid != parent.pid):
                        logger.error("Raylet is dead, exiting.")
                        sys.exit(0)
                    await asyncio.sleep(
                        dashboard_consts.
                        DASHBOARD_AGENT_CHECK_PARENT_INTERVAL_SECONDS)
            except Exception:
                logger.error("Failed to check parent PID, exiting.")
                sys.exit(1)

        if sys.platform not in ["win32", "cygwin"]:
            check_parent_task = create_task(_check_parent())

        # Create an aioredis client for all modules.
        try:
            self.aioredis_client = await dashboard_utils.get_aioredis_client(
                self.redis_address, self.redis_password,
                dashboard_consts.CONNECT_REDIS_INTERNAL_SECONDS,
                dashboard_consts.RETRY_REDIS_CONNECTION_TIMES)
        except (socket.gaierror, ConnectionRefusedError):
            logger.error(
                "Dashboard agent exiting: "
                "Failed to connect to redis at %s", self.redis_address)
            sys.exit(-1)

        # Create a http session for all modules.
        # aiohttp<4.0.0 uses a 'loop' variable, aiohttp>=4.0.0 doesn't anymore
        if LooseVersion(aiohttp.__version__) < LooseVersion("4.0.0"):
            self.http_session = aiohttp.ClientSession(
                loop=asyncio.get_event_loop())
        else:
            self.http_session = aiohttp.ClientSession()

        # Start a grpc asyncio server.
        await self.server.start()

        modules = self._load_modules()

        # Http server should be initialized after all modules loaded.
        app = aiohttp.web.Application()
        app.add_routes(routes=routes.bound_routes())

        # Enable CORS on all routes.
        cors = aiohttp_cors.setup(
            app,
            defaults={
                "*": aiohttp_cors.ResourceOptions(
                    allow_credentials=True,
                    expose_headers="*",
                    allow_methods="*",
                    allow_headers=("Content-Type", "X-Header"),
                )
            })
        for route in list(app.router.routes()):
            cors.add(route)

        runner = aiohttp.web.AppRunner(app)
        await runner.setup()
        site = aiohttp.web.TCPSite(runner, "0.0.0.0", self.listen_port)
        await site.start()
        http_host, http_port, *_ = site._server.sockets[0].getsockname()
        logger.info("Dashboard agent http address: %s:%s", http_host,
                    http_port)

        # Dump registered http routes.
        dump_routes = [
            r for r in app.router.routes() if r.method != hdrs.METH_HEAD
        ]
        for r in dump_routes:
            logger.info(r)
        logger.info("Registered %s routes.", len(dump_routes))

        # Write the dashboard agent port to redis.
        await self.aioredis_client.set(
            f"{dashboard_consts.DASHBOARD_AGENT_PORT_PREFIX}{self.node_id}",
            json.dumps([http_port, self.grpc_port]))

        # Register agent to agent manager.
        raylet_stub = agent_manager_pb2_grpc.AgentManagerServiceStub(
            self.aiogrpc_raylet_channel)

        await raylet_stub.RegisterAgent(
            agent_manager_pb2.RegisterAgentRequest(
                agent_pid=os.getpid(),
                agent_port=self.grpc_port,
                agent_ip_address=self.ip))

        tasks = [m.run(self.server) for m in modules]
        if sys.platform not in ["win32", "cygwin"]:
            tasks.append(check_parent_task)
        await asyncio.gather(*tasks)

        await self.server.wait_for_termination()
        # Wait for finish signal.
        await runner.cleanup()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Dashboard agent.")
    parser.add_argument(
        "--node-ip-address",
        required=True,
        type=str,
        help="the IP address of this node.")
    parser.add_argument(
        "--redis-address",
        required=True,
        type=str,
        help="The address to use for Redis.")
    parser.add_argument(
        "--metrics-export-port",
        required=True,
        type=int,
        help="The port to expose metrics through Prometheus.")
    parser.add_argument(
        "--dashboard-agent-port",
        required=True,
        type=int,
        help="The port on which the dashboard agent will receive GRPCs.")
    parser.add_argument(
        "--node-manager-port",
        required=True,
        type=int,
        help="The port to use for starting the node manager")
    parser.add_argument(
        "--object-store-name",
        required=True,
        type=str,
        default=None,
        help="The socket name of the plasma store")
    parser.add_argument(
        "--listen-port",
        required=False,
        type=int,
        default=0,
        help="Port for HTTP server to listen on")
    parser.add_argument(
        "--raylet-name",
        required=True,
        type=str,
        default=None,
        help="The socket path of the raylet process")
    parser.add_argument(
        "--redis-password",
        required=False,
        type=str,
        default=None,
        help="The password to use for Redis")
    parser.add_argument(
        "--logging-level",
        required=False,
        type=lambda s: logging.getLevelName(s.upper()),
        default=ray_constants.LOGGER_LEVEL,
        choices=ray_constants.LOGGER_LEVEL_CHOICES,
        help=ray_constants.LOGGER_LEVEL_HELP)
    parser.add_argument(
        "--logging-format",
        required=False,
        type=str,
        default=ray_constants.LOGGER_FORMAT,
        help=ray_constants.LOGGER_FORMAT_HELP)
    parser.add_argument(
        "--logging-filename",
        required=False,
        type=str,
        default=dashboard_consts.DASHBOARD_AGENT_LOG_FILENAME,
        help="Specify the name of log file, "
        "log to stdout if set empty, default is \"{}\".".format(
            dashboard_consts.DASHBOARD_AGENT_LOG_FILENAME))
    parser.add_argument(
        "--logging-rotate-bytes",
        required=False,
        type=int,
        default=ray_constants.LOGGING_ROTATE_BYTES,
        help="Specify the max bytes for rotating "
        "log file, default is {} bytes.".format(
            ray_constants.LOGGING_ROTATE_BYTES))
    parser.add_argument(
        "--logging-rotate-backup-count",
        required=False,
        type=int,
        default=ray_constants.LOGGING_ROTATE_BACKUP_COUNT,
        help="Specify the backup count of rotated log file, default is {}.".
        format(ray_constants.LOGGING_ROTATE_BACKUP_COUNT))
    parser.add_argument(
        "--log-dir",
        required=True,
        type=str,
        default=None,
        help="Specify the path of log directory.")
    parser.add_argument(
        "--temp-dir",
        required=True,
        type=str,
        default=None,
        help="Specify the path of the temporary directory use by Ray process.")
    parser.add_argument(
        "--session-dir",
        required=True,
        type=str,
        default=None,
        help="Specify the path of this session.")
    parser.add_argument(
        "--runtime-env-dir",
        required=True,
        type=str,
        default=None,
        help="Specify the path of the resource directory used by runtime_env.")

    args = parser.parse_args()
    try:
        logging_params = dict(
            logging_level=args.logging_level,
            logging_format=args.logging_format,
            log_dir=args.log_dir,
            filename=args.logging_filename,
            max_bytes=args.logging_rotate_bytes,
            backup_count=args.logging_rotate_backup_count)
        setup_component_logger(**logging_params)

        agent = DashboardAgent(
            args.node_ip_address,
            args.redis_address,
            args.dashboard_agent_port,
            redis_password=args.redis_password,
            temp_dir=args.temp_dir,
            session_dir=args.session_dir,
            runtime_env_dir=args.runtime_env_dir,
            log_dir=args.log_dir,
            metrics_export_port=args.metrics_export_port,
            node_manager_port=args.node_manager_port,
            listen_port=args.listen_port,
            object_store_name=args.object_store_name,
            raylet_name=args.raylet_name,
            logging_params=logging_params)
        if os.environ.get("_RAY_AGENT_FAILING"):
            raise Exception("Failure injection failure.")

        loop = asyncio.get_event_loop()
        loop.run_until_complete(agent.run())
    except Exception as e:
        # All these env vars should be available because
        # they are provided by the parent raylet.
        restart_count = os.environ["RESTART_COUNT"]
        max_restart_count = os.environ["MAX_RESTART_COUNT"]
        raylet_pid = os.environ["RAY_RAYLET_PID"]
        node_ip = args.node_ip_address
        if restart_count >= max_restart_count:
            # Agent is failed to be started many times.
            # Push an error to all drivers, so that users can know the
            # impact of the issue.
            redis_client = ray._private.services.create_redis_client(
                args.redis_address, password=args.redis_password)
            traceback_str = ray._private.utils.format_error_message(
                traceback.format_exc())
            message = (
                f"(ip={node_ip}) "
                f"The agent on node {platform.uname()[1]} failed to "
                f"be restarted {max_restart_count} "
                "times. There are 3 possible problems if you see this error."
                "\n  1. The dashboard might not display correct "
                "information on this node."
                "\n  2. Metrics on this node won't be reported."
                "\n  3. runtime_env APIs won't work."
                "\nCheck out the `dashboard_agent.log` to see the "
                "detailed failure messages.")
            ray._private.utils.push_error_to_driver_through_redis(
                redis_client, ray_constants.DASHBOARD_AGENT_DIED_ERROR,
                message)
            logger.error(message)
        logger.exception(e)
        exit(1)
